Jet spalling assembly and drill-spalling rig

ABSTRACT

A jet spalling assembly for use as a unit of a mobile drillspalling rig, comprising a plurality of telescoping tubes; an upper end section of the outermost tube disposed out of the telescoping relationship; a plurality of conduits extending into the upper end tube section through a side thereof, and then downwardly through the tubes to an externally disposed burner attached to the end of the innermost tube, for conveying materials for combustion in the burner, and water for cooling the burner during combustion; and means for discharge of separate streams of water and hot combustion product from the burner for the spalling action. The tubular spalling assembly is retractable to provide an overall length adaptable to transport on a mobile least from site to site, but is extendible at the site to accomplish spalling action at correspondingly greater borehole depths. A now preferred embodiment comprises a mobile drill-spalling assembly including a plurality of stem members including at leas one drill stem and a jet spalling unit above described, successively supportably movable into, and from, operating position, and means for operating each stem member. This embodiment provides for both drilling and spalling during a single emplacement of the mobile assembly to thereby eliminate the numerous disadvantages inherent in the prior art practice of drilling a borehole, moving the drilling unit from the site, and then moving a separate spalling unit into place for the spalling action.

United States Patent [1 1 Hopler, Jr.

[4 1 Feb. 19, 1974 JET SPALLING ASSEMBLY AND DRILL-SPALLING RIG [75] Inventor: Robert B. Hopler, Jr., Succasunna,

21 Appl. No.: 215,884

[52] US. Cl ..175/l1,175/321 [51] Int. Cl ..E21b 7/14 [58] Field of Search 175/11-17, 321, 175/52 [56] References Cited UNITED STATES PATENTS 2,694,550 11/1954 Aitchison et al 175/14 2,066,794 1/1937 Miller 175/321 656,515 8/1900 Cassity 175/321 3,493,061 2/1970 Gyongyosi 175/52 1,895,901 l/l933 Smith 175/321 X 2,738,162 3/1956 Aitchison 175/14 [57] ABSTRACT A jet spalling assembly for use as a unit of a mobile drill-spalling rig, comprising a plurality of telescoping tubes; an upper end section of the outermost tube disposed out of the telescoping relationship; a plurality of conduits extending into the upper end tube section through a side thereof, and then downwardly through the tubes to an externally disposed burner attached to the end of the innermost tube, for conveying materials for combustion in the burner, and water for cooling the burner during combustion; and means for discharge of separate streams of water and hot combustion product from the burner for the spalling action.

The tubular spalling assembly is retractable to provide an overall length adaptable to transport on a mobile least from site to site, but is extendible at the site to accomplish spalling action at correspondingly greater borehole depths.

A now preferred embodiment comprises a mobile drill-spalling assembly including a plurality of stem members including at leas one drill stem and a jet spalling unit above described, successively supportably movable into, and from, operating position, and means for operating each stem member.

This embodiment provides for both drilling and spalling during a single emplacement of the mobile assembly to thereby eliminate the numerous disadvantages inherent in the prior art practice of drilling a borehole, moving the drilling unit from the site, and then moving a separate spalling unit into place for the spalling action.

9 Claims, 12 Drawing Figures PAIENTEB FEB I 9 I974 FIG. 8A

SHEET 3 [1F 3 E mg g gs FIG. 8

FIG.8C

JET SPALLING ASSEMBLY AND DRILL-SPALLING RIG This invention relates to a jet-spalling assembly for use as an element of a drill-spalling rig. In one aspect, this invention relates to a self-propelled rig for drilling and jet spalling boreholes without the need heretofore for first drilling the borehole and then moving in a separate rig for the spalling operation. Other aspects will be apparent in light of the accompanying disclosure and the appended claims.

Self-propelled mobile drilling assemblies, or rigs, generally truck mounted, have had wide use in earth drilling operations. The assembly includes a support mast for a drill stem for the drilling operation, a stemchanging mechanism for holding and transfer of one or more drill stems to and from the mast, and means for longitudinally moving the drill stem on the mast into, and from, the drilling operation, with rotation of the stem as required. The mast is mounted on the mobile unit so as to be foldable from drilling position into an inclined position for transport, and readily unfoldable into drilling position at the drilling site. The stemchanging mechanism is similarly supported, and is generally movable with the mast into and from transport position as a single unit.

The height of the mast is of course limited in order that it be portable as a unit of the self-propelled assembly, and, accordingly, the length of the drill stem supported on the mast, and hence, the maximum depth of the borehole utilizing that drill stem, are correspondingly limited. However, the function of the stemchanging mechanism is to successively deliver additional sections of the drill stem to the mast for engagement with the drill stem already in the borehole, to accomplish deeper holes.

In drilling and blasting practice, it is often necessary to increase energy loadings at one or more zones in the borehole. Conventional bit-drilling to accomplish a sufficiently large borehole diameter for the requisite energy capacity in such zones, without effective use of the remaining portion of the borehole, is, of course, generally uneconomical. In such instances, therefore, the borehole is often enlarged locally, such as by jetspalling which involves introduction of high temperature combustion product into the borehole within the particular zone under conditions causing the rock structure to break and move from the hole as suspended particles in the combustion gases and/or as vapor.

In accordance with that procedure, the industry has, in many instances, resorted to drilling a relatively small primary hole after which the zone to be loaded with explosive is enlarged by jet-spalling to accomplish the requisite local hole dimension. That practice has generally been carried out'by first drilling the primary hole utilizing a self-propelled drilling type unit, or rig, above described, and then moving the drill rig from the drilling site and, in its place, moving in a separate jetspalling rig, for carrying out the spalling step.

The above practice involving utilization of separate rigs has been disadvantageous in many aspects. In the first place, when moving a spalling unit into position, hole alignment is critical, inasmuch as the primary drill, during the initial drilling step, has often been moved slightly off level (tilted side-to-side or front-to-rear) and the jet-spalling unit to be lowered into the hole, if

not exactly in alignment with the resulting off-level borehole, often binds in the hole to thus seriously impair the operation. Further, two separate drilling rig crews are required for the separate units, and in turn, two separate prime movers, air supplies, masts, hydraulic systems, and the like are required with attendant costs. Also, when carrying out such separate drill and spalling operations in the field, scheduling of the separate units is difiicult due to the difference in time required for the drilling and the spalling steps, with a high percentage of resulting unproductive time.

This invention is concerned with a self-propelled assembly which can be moved into drilling position for accomplishment of both the drilling and spalling steps without need for use of separate drilling and spalling units; and hence without the disadvantages inherent in carrying out separate drilling and spalling operations.

In accordance with the invention, a spalling unit for use as an element of a self-propelled drill-spalling rig is provided, which comprises a plurality of telescoping tubes, and means for moving same in said telescoping relationship; a burner member external to said tubes, and attached to an end of the innermost of said tubes; an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship; a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion product and water from said burner for the spalling action.

Generally, the spalling unit contains two concentric tubes and comprises a first open end tube, and a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendable from, said first tube through only one end thereof; an opposite end portion of said first tube disposed outside said concentric relationship; spline means for precluding axial rotation of said second tube with said first tube, and for precluding rotation of said first tube; a burner member attached to an end of said second tube outside the first tube; a hoist line extending into said first tube through said side wall and then connecting with said second tube for slidably vmoving said second tube within said first tube as described; a plurality of conduits extending into said opposite end portion of said first tube through a side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion product and water from said burner for the spalling action.

In a preferred embodiment, the invention provides a self-propelled drill-spalling rig comprising, in combination, a mast; a plurality of stem members including at least one drill stem, and a tubular jet spalling unit; means for successively supportably moving said stem members to and from said mast in longitudinal relationship therewith; means for longitudinally lowering and raising each stem member on said mast into and from the borehole; and said spalling unit comprising (1) a plurality of telescoping tubes, (2) means for moving said tubes in said telescoping relationship, (3) a burner member external to said tubes, and attached to an end of the innermost of said tubes, (4) an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship, a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner to convey materials for combustion therein, and water for cooling the burner during said combustion and (6) means for discharge of separate streams of combustion product and water from said burner for the spalling action. Generally, the spalling unit of the drill-spalling assembly is that comprising two concentric tubes, above described.

One form of the now preferred embodiment comprises a mast assembly, and means for longitudinally movably supporting a stem member on said mast assembly substantially parallel to the longitudinal axis thereof; power means in operative engagement with said stern member, when supported on said mast, for longitudinally moving same; a shaft member adjacent, and substantially parallel to, said mast assembly axis, and pivotally movable toward, and away from, said mast assembly in said parallel relationship therewith; means secured to said shaft for support of each of a plurality of stem members substantially parallel to, and equispaced from, said shaft, and movable with said shaft toward and away from said mast assembly; the arc of a pivotal movement of said shaft toward and away from said mast assembly having a radius predetermined to lead said support means secured to said shaft into, and from, operating relationship with said support means on said mast member for transfer of a stem member of said plurality from one said support means to the other; a plurality of said stem members supported by at least one of the above said support means therefor with at least one said stem member supported by said support means secured to said shaft, and said plurality of stem members including at least one drill stem, and a tubular spalling unit; said spalling unit comprising l a first open end tube, (2) a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendable from, said first tube through only one end thereof, (3) an opposite end portion of said first tube disposed outside said concentric relationship, (4) spline means for precluding axial rotation of said second tube within said first tube, and for precluding rotation of said first tube, (5) a burner member attached to an end of said second tube outside the first tube, (6) a hoist line extending into said first tube through said side wall and then connecting with said second tube for slidably moving said second tube within said first tube as described; (7) a plurality of conduits extending into said opposite end portion of said first tube through a side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and (8) means for discharge of separate streams of combustion product and water from saidburner for the spalling action.

The invention is further illustrated with reference to the drawings of which FIG. 1 is a front elevation, partly in cross-section, of

a jet-spalling assembly of the invention;

FIG. 2 illustrates a now preferred form of selfpropelled jet drill-spalling assembly including a spalling unit of FIG. 1;

FIGS. 3, 4, 5 and 6, are, respectively, views taken along the lines 3--3, 44, 5-5 and 6-6 of FIG. 1;

FIG. 7 illustrates in more detail a now preferred form of the spalling-drill assembly of FIG. 2, particularly from the standpoint of stem-changing means by which the stem members are successively transferred to and from the mast assembly for the drill-spalling operation; and

FIGS. SA-E incl. illustrate one embodiment of spalling operation utilizing a drill-spalling assembly of FIGS. 1, 2 and 3.

Referring to FIG. 1 outer tubular member 10 of tubular spalling assembly 11 contains open passageway 12 extending through a side wall of a top end section 13, and external male threads 14 at the top end 14' for threadably engaging a rotary driving member 16' further described herein. Peripheral external recessed surface 62 on member 10 intermediate passageway 12 and threads 14 is further described herein. Inner tubular member 17 is within, and concentric with, tube member 10 so as to be retractable into, and extendable from, tube 10 only through bottom end 18 thereof.

Circumferential flange 19 on the inner wall of tube 10 extends inwardly at bottom end 18. Circumferential flange 21 on tube 17 extends from the external wall thereof at the top end 22. Tube 17 is longitudinally movable through bottom end 18 of tube 10 in sufficiently close spaced relationship to flange 19 to cause flange 21 to seat on flange 19 when tube 17 is fully ex tended from tube 10, to thereby function with flange 19 as a stop to preclude longitudinal travel of tube 17 in its entirety from tube 10.

External circumferential flange 24, subjacent open passageway 12, extends outwardly from tube 10 and rib type spline member 23 extends longitudinally along the exterior surface of tube 10, from flange 24 to the bottom end 19. Plate member 26, for attachment to the support structure for the unit 11 is disposed in close proximity to the ground surface as a guide means for longitudinal travel of unit 11 into and from the borehole, and includes spline slot 27 (see FIG. 4) for engagement with spline 23 to prevent rotation of tube 10 during the spalling operation. Tubular member 17 contains external rib type spline 28 (see FIG. 5,6) extending lengthwise of tube 17 from flange 21 to the bottom end 38 thereof for engaging longitudinally extending spline groove 29 on the inner wall of flange 19 (see FIG. 6) to thereby preclude rotation of tube 10 independently of tube 17.

Sheave assembly 30 includes sheave members 31 and 32 (see also FIG. 3) maintained on a common axis 33 spaced from the axis of tube 10 but substantially parallel to the plate member 26 so as to introduce communication lines into a central area of tube 10 for longitudinal downward travel through both tubes. Line 34 is a bundle of three separate lines delivered via sheave 32 for communicating separate streams of oxygen or compressed air, fuel and water to a burner assembly at the bottom end of tube 17. Line 36 delivered via sheave 31 is a hoist line connecting with tube member 17 for purpose of retracting and extending tube member 17 into and from tube 10 and for supporting the position of tube 17, particularly when extended from tube 10, during the spalling operation.

Burner member 37 is secured to the bottom end 38 of inner tube 17 and operatively connects with line 34 to receive separate streams of the necessary fuel (34a) and oxygen or air (34b), for combustion (34c), and water for cooling the burner during the combustion; and for discharge of separate streams of hot combustion product, and water, via orifices 39 and 39', respectively, into the borehole for the spalling action.

Burner member 37, coaxially connecting with tube 17 at the bottom end 38, extends laterally beyond the confines of tube to thereby control retraction of tube 17 into tube 10, upon contact with the end 18 of tube 10, to preclude longitudinal travel of tube 17 into the top open area 12.

Tube 10 contains openings 25a through a side wall thereof and spaced apart 180 in a plane transverse to the shell 10 axis in top end section 13 intermediate flange 24 and open passageway 12. Tube 17 contains openings 25b in the side wall near top end 22 spaced apart so as to register with openings 25a at maximum retraction of tube 17 into tube 10.

Pin member 25 extends through openings 25a and also through openings 25b when the latter are in register therewith to thereby lock tube 17 in maximum retraction in tube 10. Pin 25 is engaged into and out of locking position with tubes 10 and 17, by drawing hoist line 36 to raise tube 17 to the appropriate level for alignment of the openings in registered position, and to raise the tube 17 to relieve tension on the pin to permit it to be withdrawn from the openings and hence disengaged from the locking position. In engaging pin 25 in the locking position, pin 25 is directed through the void space in the body of lines 34 and 36 downwardly extending from passageway 12, generally along a path intermediate sheaves 31 and 32.

In operation of the device of FIG. 1, the spalling unit 11 is positioned by any suitable means over the previously drilled borehole, and fuel, oxygen or compressed air, and water are passed to the burner via lines 34a, b and c (see FIG. 3) as above described. The spalling unit in any predetermined degree of extension of tube 17 from tube 10 is then lowered by any suitable means into the borehole to the requisite spalling level.

When the spalling site is below the bottom end of tube 10, i.e. at a time when tube 17 is locked at maximum retraction in tube 10 by pin 25, tube 17 is telescopically extended from tube member 10 by disengaging pin 25 from locking position and lowering hoist line 36, the latter connecting with tube 17 at any suitable point, preferably by any suitable means with the inner side wall at or near botton end 38. By regulating the length ofline 36 together with any extension of tube 17 from tube 10, burner 37 is disposed at any spalling level limited only by the length of one or both of tubes 10 and 17, as the case may be. In the embodiment shown, the maximum depth at which spalling can be accomplished is approximately twice that of the length of a single tube that can be supported on a self-propelled drilling-spalling assembly of FIG. 2 as discussed hereinafter.

After termination of the spalling step, the unit 11 is generally raised from the borehole by first drawing line 36 to raise tube 17, if extended, to the maximum retraction position in tube 10, and tubes 10 and 17 are then locked into position by pin 25. The entire unit 11 is then raised from the borehole by a suitable means such as drive assembly 16 of FIG. 2.

The spalling assembly 11 as an element of a selfpropelled drill-spalling rig as illustrated with reference to FIG. 2 is a now preferred embodiment of the invention, and provides for carrying out the drilling step, removing the drill stem-bit and, without moving the rig, emplacing the spaller assembly in true alignment with the previously drilled borehole without the time consuming, and associated equipment, and manpower, requirements characteristic of conventional operations which require that a separate drill unit be utilized and then moved from the site and a'separate spalling unit brought in. In practice of the embodiment of FIG. 2 there can be no misalignment to cause binding of the spaller unit in the borehole inasmuch as the drive means and associated supporting elements remain in their original drilling position and, hence are set to direct the spaller along precisely the same path through which the drill stern and bit were previously operated.

Referring to FIGS. 2 and 7, self-propelled drillspalling rig 41 includes truck unit 42, stem-changing mechanism 43, mast 44 and associated elements, supported thereon for ready portability for operation at different sites. As shown, stem-changing mechanism 43, which includes disc structure and associated elements for successively moving stern members into and from operating position as described hereinafter, and mast member 44, are in an upright position for the drilling and spalling operation, and are hinged by any suitable means 46 for folding into a supported inclined position 42' on assembly 42 for portability.

Mast 44 is of limitedheight, generally from 25 to 35 feet, to facilitate its portability on assembly 42. The drill stem, and tubular spalling, units, described more fully hereinafter, are of limited height accordingly, generally not exceeding about 25 feet.

Rotary type power drive means 16 is supported on mast 44, and is movable along a path substantially parallel to the longitudinal axis of mast 44. Shaft 48, is parallel to the longitudinal axis of mast 44 and is spaced from mast 44 by spaced apart parallel arms 49 and 51,

each connecting at one end with the shaft 48, and pivotally at the other end with support rod 52 parallel with mast 44 and secured in close proximity thereto. Arms 49 and 51 pivotally connect with rod 52 so as to swing about the pivot points to move shaft 48 in its position parallel with the mast 44 axis. Generally the arms 49 and 51 are parallel and thus are in separate planes normal to the mast 44 axis.

Disc members 53 and 54 are coaxially secured to shaft 48 and are spaced apart intermediate arms 49 and 51, and they serve as support means for a plurality of stem members including at least one drill stern and a tubular spalling assembly 11 of FIG. 1, and to successively transfer the stem members to the mast for engagement with the drive means 16 and subsequent removal from the mast.

Power head 16 for raising and lowering the stem members, i.e. a drill stem or tubular spalling unit, with optional rotation of the drill stem, and optional rotation of the spalling unit through a limited angle, say a maximum of about 45, is supported on mast 44 and threadably connects through rotary drive shaft 16 with threaded top end 14 of a spalling unit 11 of FIGS. 1 and 2, and coaxially therewith; or, alternatively, with a similarly threaded end of a conventional drill stern, either of which stern member has been moved to the mast for engagement with drive means 16, from stem-changing unit 43.

Support rod member 52 in close spaced parallel relationship with mast 44 is supported at each end by bracket means 56 extending from mast 44. Arms 49 and 51 each pivotally connect with rod 52 by bracket 56 so as to pivot about rod 52 and swing in parallel planes substantially normal to rod 52. Arms 49 and 51 resp. connect with shaft 48, at the top and bottom ends thereof. Intermediate arms 49 and 51 are disc members 53 and 54. Upper disc 53 contains a plurality of peripherally disposed spaced apart passageways 58 each equidistant from shaft 48, and key way 59 extending through the disc 53 and opening from a passageway 58 through the periphery of the disc.

On bottom disc 54, and facing disc 53 are disposed support members 61 each facing disc member 53 on a line parallel to shaft 48 in alignment with a corresponding passageway 58 of disc 53, i.e. as a seatingpassageway pair on a common longitudinal axis parallel to shaft 48. Each element 61 is adapted to support a bottom end of one stem member, when the latter extends from a passageway 58 parallel to shaft 48.

Each stem member, i.e. a drill stem, or a tubular assembly 11 of FIG. 2, to be supported on the disc support means 53 and 54 has a recessed peripheral external surface 62 in close proximity to the top end, i.e. to be associated with passageways 58 and 59. Each peripheral opening 58 is of size to encompass a tubular member when extending longitudinally therethrough, and each key way 59 is too small to encompass the tubular member at a full cross-sectional dimension but is sufficiently large to encompass the recessed portion of each tube.

Although only one drili stem member and one tubular spalling assembly 11 are required for operation of the rig of FIGS. 2 and 7, it is generally preferred that from two to six drill stems 11 be carried and that one jet spalling unit 11 be in the assembly, i.e. supported either on mast 44 or on stem-changing means 43.

In operation of the stem-changing means 43, rotation of support rod 52 is accomplished by action of a suitable hydraulically operated piston assembly 63, supported on mast 44 with piston rod 66 extending to bracket 55 fixed to rod 52. Piston rod 66 is operatively connected with bracket 64 to drive bracket 55 to rotate rod 52 on its longitudinal axis and, to hence move arms 49 and 51 on their pivotal points to, or away from, the mast member 44, as illustrated with reference to the arc A-B. Rod 52 is rotated counterclockwise in response to forward travel of piston rod 66 to pivotally move arms 49 and 51 on shaft 48 on the arc A-B toward mast 44 to position ll. When the rotation of rod 52 is clockwise, i.e. in response to retraction of piston rod 66, shaft 48 is rotated on the arc A-B with pivotal travel of the arms away from mast 44 to position I.

Stem-changing mechanism 43 in position I is out of operating position with reference to drive means 16 on mast 44; and in position II it is in operating relationship for transfer of a stem member to, or from, operating position on mast 44.

Shaft 48, rigidly connecting with arms 49 and 51 moves disc support means 53 and 54 to and from mast 44 on the arc A-B and the radius of the are on which the shaft 48 moves intermediate position I and ll is regulated by the length of arms of 49 and 51 so as to move the stem member supported by discs 53 and 54, and

closest to the longitudinal axis of travel of the drive means 16, into axial alignment with the longitudinal axis of travel of drive means 16. In that manner, the passageway 58 containing a stem member 11, or 11', and the support member 61 in lower disc 54 are substantially coaxially disposed on an axis common with the line of longitudinal travel of the drive member 16.

The discs 53 and 54 are loaded with stem members from rack 68 (FIG. 2) supported by, and parallel with, mast 44 by moving each individual stem member from rack 68 on jib crane 67 in accordance with conventional practice not further illustrated. Each stem member is moved from storage by jib member 67 into a passageway 58 by aligning the peripherally recessed portion 62 of the stem member with the key way, the bottom disc 54 being, at that point, spaced from disc 53 so as to be free from the bottom end of the stem member, but so spaced that when the stem member is emplaced in the passageway 58 from the jib crane and the stem member is then lowered to dispose the full crosssectional dimension of the stem in the passageway, the bottom end of the stem is seated in the seating means 61, at which time the peripheral recessed portion 62 is subjacent disc member 53. By rotation of rod 52 counterclockwise, the disc members 53 and 54 are moved along the arc A-B to emplace the tubular member from the rack in alignment with power head drive means 16 on mast 44.

At that point power head 16 is lowered by conventional means not shown and rotated to threadably engage rotary shaft 16 with the top end 14 of the tubular member. The power means is then raised to dispose the tubular member upwardly sufficiently to unseat it from its support member 61 and register. the circumferential recess 62 with the key way 59 associated with the corresponding passageway 58.

The key way 59, in each instance at the time of emplacement of a stem member in position for engaging the drive means on mast 44 extends from the corresponding passageway 58 in a direction so as to clear the circumferential recess when the shaft 52 is rotated to move the stem-changing mechanism into position I from mast 44. The power drive is then lowered to drive the stem member longitudinally downward to initiate the drilling, or spalling, operation. The drilling operation is carried on in accordance with conventional rotary, or downhole, drilling procedure, in all embodiments of which the drill-bit is secured to the bottom end of the initially emplaced drill stem for the drilling procedure in accordance with conventional practice not further described herein.

Conventional indexing means 60 comprises piston rod 64 driven alternately forward and in reverse, by piston 64a, and disc type perforate head member 65 coaxially connecting with shaft 48 below arm 51. By pin means, not shown, secured manually through the rod and perforations of head 65, rod 64, in response to action of piston 64a, engages head 65 to drive it in a predetermined degree of rotation to correspondingly rotate shaft 48 for alignment of any given seatingpassageway pair (61, 58) on mast 44 for transfer of a stem member to or from the mast. Indexing means 60, with appropriate manual handling of the pin means for connecting rod 64 with head 65, conventionally provides for cyclic operation to effect successive transfer of all stem members to and from the mast.

After the predetermined number of drill stems has been introduced into the drill string, i.e. by successively transferring a plurality of drill stems from the stemchanging mechanism to the mast and engaging each with the drive means at the top, and at the bottom end with the previously driven drill stem, and the drilling is terminated, each drill stem is raised from the borehole onto the mast for disengagement from the drill string and transfer to the stem-changing mechanism. A spalling unit 1 1 of FIG. 2 is then delivered to operating position on the mast from the stem-changing mechanism, and is lowered by lowering the drive means 16 to the requisite level for the spalling step.

In some instances the spalling level may be sufficiently deep that it cannot be reached by the fully telescoped assembly 11; and, in that event, by removal of 'pin 25 from retraction locking relationship with tubes and 17 after the assembly 11 is in its lowermost position, i.e. with flange 24 resting on plate 26, and by extending hoist line 36 from sheave 31, tubular member 17 is gravitationally extended from tube member 10 for access to the spalling level. Although for purpose of portability of the combined assembly on the truck unit, the length of each individual tubular member 10 and 17 is limited to provide a fully retracted assembly 11 having a length not greater than about 25 feet, the spalling device can be extended to reach a depth in the order of an additional 25 feet.

When the tubular unit is returned to the mast from the borehole for transfer to the tube-changing mechanism, the latter is rotated about the arc A-B to position II; and, when discs 53 and 54 are then in full supporting engagement with the stem member, shaft 48 is moved along the arc A-B to position I.

In the rig assembly of FIGS. 2 and 7, supported in position I, the perforate plate member 26 is operatively secured to the rig near ground level so as to place its central opening substantially in complete axial alignment with the spalling assembly supported by discs 53 and 54, i.e. in a plane substantially normal to the longitudinal axis of the spalling assembly. The central opening, formed in plate 26 is of size adapted to encompass the outer tube 10 extending longitudinally therethrough and to serve as a guide for tube 10 in its downward travel to the requisite level in the borehole. Plate 26 is formed into sections in abutting relationship on a line extending across the perforation or opening therein, so that the separate parts can be assembled around the tube 10, and then into closing position as the requisite guide-support means therefor. In practice, the tubular member 1 l is first engaged with power unit 16, and the latter is then lowered sufficientlyto permit manual emplacement of plate 26 in supporting position around tube 10.

Flange 24 radially extends from tube 10 beyond the confines of the perforation, or passageway, in plate 26 so as to seat on plate 26 at the predetermined forwardmost point of travel of tube 10 as a stop means to preclude further downward longitudinal travel of tube 10.

FIGS. 8 A-E, with reference also to parts shown in FIGS. 2 and 7, further illustrate sequential operation of the spalling unit of the invention as an element of a drill-spalling assembly of FIGS. 2 and 7.

Each of lines 34a, b, and c of line 34, is connected to reel assembly 50 via conventional quick coupler means 35 for receiving the separate streams of combustible mixture ingredients, and water, initially introduced into, and delivered from, the reel hub assembly in accordance with conventional practice (not shown).

As tube assembly 11 is lowered into the borehole, the lines 34 (a, b and c) and 36 are directed over sheaves 32 and 31, resp. As the unit 11 is raised and retracted, hoist line 36 and line 34 containing the three strands 34a, b and 0, including any portions not incorporated within the single strand cover, are wound onto their respective reels. Although the reel assemblies can be positioned at any suitable location, they are advantageously disposed on the drilling rig in close proximity to plate 26, as illustrated.

Referring to FIG. 8 A, spalling unit 11 is emplaced on mast 44, connected with drive means 16, and supported in plate 26 at maximum degree of retraction of tubular member 17 in tube 10. At that point, lines 34 and 36 extending from assembly 11, as illustrated with reference to FIGS. 2, 7 and 8 A (dotted line), are connected by connectors 35 and 35 resp. to their corresponding extension lines on reels 50 and 50. As shown in FIG. 8 A, unit 11, locked in full retraction by pin 25, is in readiness for lowering to the requisite borehole level at a depth up to and including that limited only by the available length of tubular member 10, generally not in excess of from about 20-25 feet.

FIG. 8 C shows unit 11 in fully extended position provided by removing pin 25 from its retraction locking relationship with tubes 10 and 17 and by releasing all tension on hoist line 36 to seat flange 24 on plate 26, thereby permitting tubular member 17 to gravitate to its fully extended position at a total depth in the borehole limited only by the combined available lengths of tubes 10 and 17, generally in order from about 45 to 50 feet.

FIG. 8 D illustrates retraction of tube 17 from the spalling site, by winding hoist line 36 onto reel 50 and insertion of pin 25 into its retraction locking position, to bring burner 37 immediately subjacent the bottom end of tube 10; and FIG. 8 E shows the fully retracted unit 11 lifted from the borehole, by action of drive means 16, into position on the mast for transfer to the stem-changing mechanism.

In carrying out the sequential operation of FIGS. 8 A-E the combustion is initiated while the unit 11 is in the position of FIG. 8 A, by passing the fuel and oxygen or air to the burner through lines 34a and b, and lighting the resulting combustible mixture at the discharge end of orifices 39. Water flow through line 34c is generally initiated while the unit 11 is in the position FIG. 8 A, although it can be initiated subsequently, as desired.

The unit 11 can be lowered or raised as illustrated with reference to FIGS. 8 A-E to vary the spalling action at the entire, or any local portion, of the borehole interface adjacent the burner 37.

Although the reel assembly 50, shown in the drawings, is advantageously utilized, the single strand 34 containing lines 34a, b and 0 connecting with the ignition ingredient sources above illustrated, can be handled manually, without need for reel assembly means, during travel of unit 11 in the borehole.

Although the invention has been specifically illustrated with reference to a spalling assembly having two concentric tubes, viz. tubes 10 and 17, one or more additional tubes can be disposed in the defined telescopic relationship to provide a readily portable retracted unit extendable to correspondingly greater borehole depths.

Although the invention is defined herein with reference to a self-propelled assembly, it is to be understood that any such mobile assembly is within the scope of the invention independently of the means by which it is moved from one site to another.

Although a now preferred embodiment of the invention is described with specific reference to a selfpropelled assembly of FIG. 2, it is to be understood that any mobile assembly comprising a combination of stem members including at least one drill stern, and a tubular jet spalling unit above described, and means for successively supportably moving said stem members on said assembly to and from operating position, is within the scope of the invention.

As will be evident to those skilled in the art, various modifications can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the claims.

What I claim and desire to protect by Letters Patent 1. A jet spalling assembly for use as an element of a mobile drill-spalling rig which comprises a plurality of telescoping tubes, and means for moving same in said telescoping relationship; a burner member external to said tubes, and attached to an end of the innermost of said tubes; an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship; a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion product and water from said burner for the spalling action.

2. A jet spalling assembly for use as an element of a mobile drill-spalling rig which comprises a first open end tube, and a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendible from, said first tube through only one end thereof; an opposite end portion of said first tube disposed outside said concentric relationship; spline means for precluding axial rotation of said second tube within said first tube, and for precluding rotation of said first tube; a burner member attached to an end of said second tube outside the first tube; a hoist line extending into said first tube through a side wall of said opposite end portion thereof and then connecting with said second tube for slidably moving said second tube within said first tube as described; a plurality of conduits extending into said opposite end portion of said first tube through said side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion product and water from said burner for the spalling action.

3. A mobile rig for drilling and spalling boreholes, comprising a mast assembly, and means for longitudinally mov- 6 ably supporting a stem member on said mast assembly substantially parallel to the longitudinal axis thereof;

power means in operative engagement with said stern member, when supported on said mast, for longitudinally moving same;

a shaft member adjacent, and substantially parallel to, said mast assembly axis, and pivotally movable toward, and away from, said mast assembly in said parallel relationship therewith;

means secured to said shaft for support of each of a plurality of stem members substantially parallel to, and equispaced from, said shaft, and movable with said shaft toward and away from said mast assemy;

the arc of pivotal movement of said shaft toward and away from said mast assembly having a radius predetermined to lead said support means secured to said shaft into, and fromQoperating relationship with said support means on said mast member for transfer of a stem member of said plurality from one said support means to the other;

a plurality of said stem members supported by at least one of the above said support means therefor, with at least one said stem member supported by said support means secured to said shaft, and said plurality of stem members including at least one drill stem, and, a tubular spalling unit;

said spalling unit comprising (1) a first open end tube, (2) a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendible from, said first tube through only one end thereof, (3) an opposite end portion of said first tube disposed outside said concentric relationship, (4) spline means for precluding axial rotation of said second tube within said first tube, and for precluding rotation of said first tube, (5) a burner member attached to an end of said second tube outside the first tube, (6) a hoist line extending into said first tube through said side wall and then connecting with said second tube for slidably moving said second tube within said first tube as described, (7) a plurality of conduits extending into said opposite end portion of said first tube through a side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion, and (8) means for discharge of separate streams of combustion product and water from said burner for the spalling action.

4. A rig assembly of claim 3 including a pair of spaced apart arm members for pivotally movably supporting said shaft member, each arm pivotally connecting at one end with said mast member and at the other end with said shaft member, and

means for pivotally moving said arm members to move said shaft on said arc;

a disc member rotatably connecting coaxially with said shaft in each of upper and lower end portions thereof intermediate said arm members;

a plurality of spaced apart passageways extending through a peripheral portion of said upper disc toward said lower disc, and dimensioned to encompass one said stem member longitudinally extending therthrough, and a key way in said upper disc laterally opening through the periphery thereof from each said passageway;

each of said plurality of stem members having an external circumferential recess adjacent one end, dimensioned to be encompassed by any one of said key ways;

a plurality of seating means secured to said lower disc and facing said passageways and each dimensioned to receive the opposite end of one of said stem members, and each said seating means aligned with one said passageway to form a seating-passageway pair disposed on substantially a common axis parallel to said shaft;

the passageway and seating means of each pair spaced apart so as to dispose said recessed portion of said stem member subjacent said passageway when said stem member extends therethrough and is seated by said seating means, and to register said recessed portion with said key way when said stem member is raised to unseat it from said seating means;

power means longitudinally movable on said mast assembly and adapted to engage a stem member as said support therefor and drive said stem member longitudinally on said mast, and adapted to optionally rotate said stem member when engaged therewith;

said shaft being pivotally movable toward said mast to dispose one of said passageways of said upper disc member subjacent said drive means and substantially coaxially with a longitudinal axis of travel thereof, and each key way then extending so as to align with, and clear, said recessed portion when said stem member is raised and said shaft is pivotally moved away from said mast member;

means for engaging said power drive with a stem member when seated and supported as described, and for then raising said power unit to unseat said stern member from said seating means; and

means for lowering said drive means to move said stem member engaged therewith along aid longitudinal path for ingress into the drilling site.

5. A rig assembly of claim 3 wherein said spalling member is engaged with said power means for lowering into a borehole.

6. In a device of claim 4, means for periodically rotating said disc members on their common axis to successively move each passageway-seating pair into position for disposing said recessed stem portion subjacent said open passageway.

7. A mobile assembly of Claim 6 which is selfpropelled.

8. A mobile drill-spalling rig comprising, in combination, a mast; a plurality of stem members including at least one drill stem, and a tubular jet spalling unit; means for successively supportably moving said stern members to and from said mast in longitudinal relationship therewith; means for longitudinally lowering and raising each stem member on said mast into and from the borehole; and said spalling unit comprising (1) a plurality of telescoping tubes, (2) means for moving said tubes in said telescoping relationship, (3) a burner member external to said tubes, and attached to an end of the innermost of said tubes, (4) an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship, (5) a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner to convey materials for combustion therein, and water for cooling the burner during said combustion, and (6) means for discharge of separate streams of combustion product and water from said burner for the spalling action.

9. A mobile assembly comprising a combination of stem members including at least one drill stem, and a tubular jet spalling unit, means for successively supportably moving said stem members on said assembly into and from operating position, means for operating said stem members in said operating position, and said spalling unit comprising (1) a plurality of telescoping tubes, (2) means for moving said tubes in said telescoping relationship, (3) a burner member external to said tubes, and attached to an end of the innermost of said tubes, (4) an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship, (5) a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner to convey materials for combustion therein, and water for cooling the burner during said combustion, and (6) means for discharge of separate streams of combustion product and water from said burner for the spalling action.

233 33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated g hn m 19, 1214 Robert B. Hopler, Jr.

Patent No. 3,792,7 5}.

Inventor-(s) It is certified .that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

" least should In the Abstract, line 15,

read assembly line 20, leas should read least Column 1, line 63, aspects should read respects In the Claims, Column 12, line 66", 'th erthrough should read therethrough Column 13, line 39, aid should read said Signed and sealed this 11th day of June 197i.

(SEAL) Attest: v

ELWARD M.FLETCHER,JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A jet spalling assembly for use as an element of a mobile drill-spalling rig which comprises a plurality of telescoping tubes, and means for moving same in said telescoping relationship; a burner member external to said tubes, and attached to an end of the innermost of said tubes; an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship; a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion product and water from said burner for the spalling action.
 2. A jet spalling assembly for use as an element of a mobile drill-spalling rig which comprises a first open end tube, and a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendible from, said first tube through only one end thereof; an opposite end portion of said first tube disposed outside said concentric relationship; spline means for precluding axial rotation of said second tube within said first tube, and for precluding rotation of said first tube; a burner member attached to an end of said second tube outside the first tube; a hoist line extending into said first tube through a side wall of said opposite end portion thereof and then connecting with said second tube for slidably moving said second tube within said first tube as described; a plurality of conduits extending into said opposite end portion of said first tube through said side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion; and means for discharge of separate streams of combustion prodUct and water from said burner for the spalling action.
 3. A mobile rig for drilling and spalling boreholes, comprising a mast assembly, and means for longitudinally movably supporting a stem member on said mast assembly substantially parallel to the longitudinal axis thereof; power means in operative engagement with said stem member, when supported on said mast, for longitudinally moving same; a shaft member adjacent, and substantially parallel to, said mast assembly axis, and pivotally movable toward, and away from, said mast assembly in said parallel relationship therewith; means secured to said shaft for support of each of a plurality of stem members substantially parallel to, and equispaced from, said shaft, and movable with said shaft toward and away from said mast assembly; the arc of pivotal movement of said shaft toward and away from said mast assembly having a radius predetermined to lead said support means secured to said shaft into, and from, operating relationship with said support means on said mast member for transfer of a stem member of said plurality from one said support means to the other; a plurality of said stem members supported by at least one of the above said support means therefor, with at least one said stem member supported by said support means secured to said shaft, and said plurality of stem members including at least one drill stem, and, a tubular spalling unit; said spalling unit comprising (1) a first open end tube, (2) a second open end tube within, and concentric with, said first tube and slidably movable therein so as to be telescopically retractable into, and extendible from, said first tube through only one end thereof, (3) an opposite end portion of said first tube disposed outside said concentric relationship, (4) spline means for precluding axial rotation of said second tube within said first tube, and for precluding rotation of said first tube, (5) a burner member attached to an end of said second tube outside the first tube, (6) a hoist line extending into said first tube through said side wall and then connecting with said second tube for slidably moving said second tube within said first tube as described, (7) a plurality of conduits extending into said opposite end portion of said first tube through a side wall thereof and then longitudinally through said first and second tubes to said burner member to convey materials for combustion therein, and water for cooling the burner during said combustion, and (8) means for discharge of separate streams of combustion product and water from said burner for the spalling action.
 4. A rig assembly of claim 3 including a pair of spaced apart arm members for pivotally movably supporting said shaft member, each arm pivotally connecting at one end with said mast member and at the other end with said shaft member, and means for pivotally moving said arm members to move said shaft on said arc; a disc member rotatably connecting coaxially with said shaft in each of upper and lower end portions thereof intermediate said arm members; a plurality of spaced apart passageways extending through a peripheral portion of said upper disc toward said lower disc, and dimensioned to encompass one said stem member longitudinally extending therethrough, and a key way in said upper disc laterally opening through the periphery thereof from each said passageway; each of said plurality of stem members having an external circumferential recess adjacent one end, dimensioned to be encompassed by any one of said key ways; a plurality of seating means secured to said lower disc and facing said passageways and each dimensioned to receive the opposite end of one of said stem members, and each said seating means aligned with one said passageway to form a seating-passageway pair disposed on substantially a common axis parallel to said shaft; the passageway and seating means of each pair spaced apart so as to dispose said recessed portion of said stem member subjacent said passageway when said stem member extends therethrough and is seated by said seating means, and to register said recessed portion with said key way when said stem member is raised to unseat it from said seating means; power means longitudinally movable on said mast assembly and adapted to engage a stem member as said support therefor and drive said stem member longitudinally on said mast, and adapted to optionally rotate said stem member when engaged therewith; said shaft being pivotally movable toward said mast to dispose one of said passageways of said upper disc member subjacent said drive means and substantially coaxially with a longitudinal axis of travel thereof, and each key way then extending so as to align with, and clear, said recessed portion when said stem member is raised and said shaft is pivotally moved away from said mast member; means for engaging said power drive with a stem member when seated and supported as described, and for then raising said power unit to unseat said stem member from said seating means; and means for lowering said drive means to move said stem member engaged therewith along said longitudinal path for ingress into the drilling site.
 5. A rig assembly of claim 3 wherein said spalling member is engaged with said power means for lowering into a borehole.
 6. In a device of claim 4, means for periodically rotating said disc members on their common axis to successively move each passageway-seating pair into position for disposing said recessed stem portion subjacent said open passageway.
 7. A mobile assembly of Claim 6 which is self-propelled.
 8. A mobile drill-spalling rig comprising, in combination, a mast; a plurality of stem members including at least one drill stem, and a tubular jet spalling unit; means for successively supportably moving said stem members to and from said mast in longitudinal relationship therewith; means for longitudinally lowering and raising each stem member on said mast into and from the borehole; and said spalling unit comprising (1) a plurality of telescoping tubes, (2) means for moving said tubes in said telescoping relationship, (3) a burner member external to said tubes, and attached to an end of the innermost of said tubes, (4) an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship, (5) a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner to convey materials for combustion therein, and water for cooling the burner during said combustion, and (6) means for discharge of separate streams of combustion product and water from said burner for the spalling action.
 9. A mobile assembly comprising a combination of stem members including at least one drill stem, and a tubular jet spalling unit, means for successively supportably moving said stem members on said assembly into and from operating position, means for operating said stem members in said operating position, and said spalling unit comprising (1) a plurality of telescoping tubes, (2) means for moving said tubes in said telescoping relationship, (3) a burner member external to said tubes, and attached to an end of the innermost of said tubes, (4) an end portion of the outermost of said tubes, opposite said burner member, disposed outside said telescoping relationship, (5) a plurality of conduits extending into said outermost tube through a side wall of said end portion thereof and then longitudinally through said tubes to said burner to convey materials for combustion therein, and water for cooling the burner during said combustion, and (6) means for discharge of separate streams of combustion product and water from said burner for the spalling action. 